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          <div class="quiz-container">
            <div class="quiz-header">
              <h1>消息重试机制与配置 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
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      <script>
        const quizData = [
  {
    "question": "在RocketMQ中，消费者的以下哪种行为不会自动触发消息的重试机制？",
    "options": [
      "在消息处理逻辑中抛出了一个未被捕获的异常。",
      "消费处理时间超过了设定的`consumeTimeout`值。",
      "尽管内部发生了可处理的错误，但在`catch`块中记录日志后，最终返回了`ConsumeConcurrentlyStatus.CONSUME_SUCCESS`。",
      "业务逻辑判断当前无法处理该消息，并显式返回`ConsumeConcurrentlyStatus.RECONSUME_LATER`。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "消息重试机制被触发的前提是消费失败。当消费者返回`CONSUME_SUCCESS`状态时，无论其内部逻辑发生了什么，它都在向Broker明确表示“这条消息已经成功处理完毕”，因此Broker会更新消费位点，不会进行重试。而返回`RECONSUME_LATER`、抛出未捕获异常或消费超时，都是消费失败的明确信号，会触发重试。",
    "source": "文档中「RocketMQ消息重试的触发条件」部分",
    "hint": "重试机制是为处理消费失败而设计的。思考一下哪个选项代表了消费“成功”的最终状态。"
  },
  {
    "question": "关于RocketMQ中普通消息和顺序消息的默认重试策略，以下哪个说法是正确的？",
    "options": [
      "顺序消息为了保证顺序，默认不支持重试；而普通消息默认重试16次。",
      "普通消息和顺序消息的默认重试次数都是16次。",
      "顺序消息会无限重试直至消费成功，而普通消息默认有16次的重试上限。",
      "普通消息会无限重试，而顺序消息默认重试16次。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "为了严格保证消息的顺序性，如果一条顺序消息消费失败，它必须被不断重试直到成功，否则后续消息将永远无法被消费。因此，顺序消息的默认策略是无限重试。相比之下，普通消息的消费失败不会阻塞其他消息，因此它有一个默认的16次重试上限，超过后会进入死信队列。",
    "source": "文档中「重试次数配置」部分",
    "hint": "考虑一下“顺序”这个特性对重试失败的容忍度有多高。"
  },
  {
    "question": "RocketMQ默认的重试间隔策略是什么样的？",
    "options": [
      "采用固定的重试间隔，默认为30秒一次。",
      "采用退避策略，重试间隔会随着重试次数的增加而逐渐延长。",
      "重试间隔是随机的，以避免所有失败消息在同一时间点重试。",
      "没有默认策略，必须在Broker配置文件中通过`messageDelayLevel`参数手动指定。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "RocketMQ采用的是一种被称为“退避策略”的延迟等级机制。首次重试的间隔较短（如10秒），随后的重试间隔会逐渐变长（如30秒、1分钟、2分钟...）。这种设计可以避免因暂时性问题导致消息被频繁地无效重试，给下游服务或资源留出恢复时间。",
    "source": "文档中「重试间隔配置」部分",
    "hint": "文档中提到了“退避策略”，并列出了一系列从短到长的时间间隔。"
  },
  {
    "question": "在RocketMQ的哪种消费模式下，系统默认不提供消息重试功能，需要消费者自行实现相关逻辑？",
    "options": [
      "顺序消费模式 (Sequential Consumption)",
      "集群消费模式 (Cluster Consumption)",
      "广播消费模式 (Broadcast Consumption)"
    ],
    "correctAnswerIndex": 2,
    "explanation": "在广播消费模式下，消息会投递给订阅该主题的所有消费者实例。由于每个消费者都是独立消费，Broker不负责为广播模式管理消费进度和失败重试。因此，如果需要重试，必须由消费者应用自己捕获异常并实现重试逻辑。而集群消费和顺序消费模式都内置了完善的重试机制。",
    "source": "文档中「不同消费模式的重试策略」部分",
    "hint": "思考一下哪种模式下，消息是发给“所有”订阅者，使得中心化的重试管理变得不切实际。"
  },
  {
    "question": "当一条消息消费失败后，它会被发送到重试队列。关于这个重试队列，以下描述正确的是？",
    "options": [
      "所有消费失败的消息都会进入一个全局的、名为`%RETRY%_GLOBAL_TOPIC`的公共重试队列。",
      "重试队列的名称格式为`%RETRY%+Topic名`，同一个Topic下的所有消费者共享一个重试队列。",
      "重试队列是按消费组隔离的，其名称格式为`%RETRY%+消费组名`。",
      "消息不会被发送到新队列，而是在原始Topic中被标记为“待重试”，并延迟推送。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "RocketMQ的重试机制是与消费组（Consumer Group）绑定的。每个消费组都有一个自己专属的重试队列，用于暂存该组消费失败的消息，从而实现重试逻辑的隔离。这个专属队列的命名规范是`%RETRY%`前缀加上消费组的名称。",
    "source": "文档中「重试队列的基本概念」部分",
    "hint": "文档强调了重试队列的“专属”特性，它是为哪个实体专属的呢？"
  },
  {
    "question": "对于一条普通消息，在集群消费模式下，当它达到最大重试次数后仍然消费失败，它的最终去向是哪里？",
    "options": [
      "被Broker永久删除，并记录一条警告日志。",
      "被发往一个专用的死信队列（Dead-Letter Queue）。",
      "继续留在重试队列中，等待管理员手动处理。",
      "被重新发送回原始Topic的队尾。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "为了避免消息无限重试失败而丢失，RocketMQ设计了死信队列机制。当一条消息的重试次数达到上限后，它将不再被投递给消费者进行重试，而是被发送到与该消费组对应的死信队列（DLQ）中。这使得开发或运维人员可以后续对这些“处理失败”的消息进行审查和人工干预。",
    "source": "文档中「重试消息的处理流程」部分",
    "hint": "在流程图的末尾，当“超过最大重试次数”时，消息流向了哪里？"
  },
  {
    "question": "文档在“最佳实践”中强调要“实现幂等消费”。这在处理重试消息时为何至关重要？",
    "options": [
      "为了提高消息消费的吞吐量和性能。",
      "为了确保即使消息被重复投递和处理，业务的最终结果也是正确的，避免产生副作用（如重复下单）。",
      "为了保证消息严格按照发送的顺序被消费。",
      "幂等性可以减少消息在网络传输中丢失的风险。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "幂等性指的是一个操作执行一次和执行多次所产生的影响是相同的。由于重试机制会导致同一条消息被消费者多次接收和处理，如果消费逻辑不具备幂等性，就可能导致数据错误，例如重复创建订单、重复扣款等。因此，确保消费逻辑的幂等性是使用消息队列重试功能时必须遵守的核心原则。",
    "source": "文档中「重试机制的最佳实践」部分",
    "hint": "“幂等”的核心思想是“多次操作等于一次操作的效果”。思考一下为什么在“重试”场景下这个特性如此重要。"
  }
];
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        let score = 0;
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            nextBtn.style.display = 'block';
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            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
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            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  